In 1986 five-year-old Saroo (Sunny Pawer, in one of the most astonishing performances by a young child ever captured on film) was living with his widowed mother and two siblings in a rural area of central India. His mother worked as a laborer (she literally lifted rocks all day); Saroo and an older brother stole lumps of coal from passing trains, trading them for food.

On one nighttime outing, Saroo was separated from his brother and found himself locked inside an empty passenger train being driven more than 1,000 miles to Calcutta to be decommissioned.

Little Saroo didn’t know his family’s last name or the town he hailed from. Worse, he spoke only Hindi, while the Calcuttans spoke Bengali.

For months the child lived on the street — begging, stealing, avoiding capture by criminals seeking child prostitutes. After several close calls Saroo found himself in an orphanage where, miraculously enough, he was paired with an Australian couple, John and Sue Brierley (David Wenham, Nicole Kidman).

Relocated to middle-class comfort in Tasmania, the lost boy seemed to have washed up in paradise. Not even the addition to the family of his troubled adopted brother, Mantosh — like Saroo an Indian orphan but with severe emotional and social issues — could seriously erode the fairy-tale quality of Saroo’s good fortune.